Handpiece for dental engines



R. G. STANBROUGH. 'HANDPIECE Fon DENTAL` ENGINES.

APPLICATION FILED FEB. 20, 1920.

m. m m

wm M ,n U

www

me D R. G. STANBROUGH.

HANDPIECE FOVR DENTAL ENGINES. APPLICATION FILED FEB. 2o, 1920.

1,388,617. Pawntedmg 23,1921.

2 SHEETSwSHEET 2.

r A. I

II lill/lll Afro/INEIl IEW /WE/vro UNITED STATES PATENT OFFICE.

RUFUS G. STANBROUGH, OFYNEW YORK, N. Y., ASSIGNOR TOMAKRGARET E. N. STAN- BROUGH, OF NEW YORK, N. Y.

HANDPIECE FOR DENTAL ENGINES.

Specification of Letters Patent.

Patented Aug. 23, 1921.

Application filed February 20, 1920.` SerialiNo. 360,032."

To all whom t may concern:

Be it known that I, Runes STAN- nnouei-I, a citizen of the United` States, residing at New Yorlnin; the county of New York and State of New York, have invented certain new and useitul Improvements in Handpicces for Dental Engines; and I do hereby Vdeclare the; following to be a full, clear, and exact description ot' the invention,

such as will enable others skilled in the `art l rior surfaces adapted `to co-act with a sta-` tionary conical recessed portion near the outer end oit the inner sleeve of the hand piece. and a similar recessed portion on a longitudinally movable chuck closer, operated by thrust movement to` close the double chuck upon the drill `or tool, and the chuck closer is ordinarily operated by means of a` dogr or lever' oifzpeculiarconstruction provided with a ulcrumportion having pivotal ears engaging recessed portions in the inner sleeve oil. the hand piece, a tail or lever movable laterallyoi the hand piece by means ot C a wedge piece, which is capable oi move-l ment longitudinally ot the hand piece, the dog being provided with an angular shoulu der to engage the chuck closer, to impart` thrust movement thereto. This construction is objectionable in its operation in that the thrust ot the dog is applied to the chuck closer at one Vside of its longitudinal airis, which tends to throwthe chuck closerout olf alincrncnt with the` longitudinal aXis of the` sleeve; and to `produce a `bind ofthe chuck closerwithinsaid sleeve and 'interfere with the correct operation o'l. the chuck,and further.` the construction of the donf, which mus be formed with the utmost nicety and accuracy, ,to producethc pivotal ears, theau-` gular `shoulder-` and i the i elongated tail or lever portion in a single piece o'tmetal, is a very expensive operation requiring;` a succession of machine operations with tools and chucks thereby greatly increasingithe cost oi production of such hand pieces. Moreover, in the `ordinary hand piece so constructed, there is no means for adjusting the device for the `purpose of regulating the bite of the` double chuck, or for the purpose of .taking up wear, without disassemblingl `the hand piece, such` adjustment being ordinarily ac complishcd by means of washers interposed between portions of the chuck closingudevice, and such adjustment can only be made by removing the washer and` replacing it with another oi' different thickness, while the hand piece is disassembled.

The objects of my invention areto sim-` plify the construction and cheapen the cost `of manufacture of `such dental `hand pieces,

without in any way impairing their eiliciency, and at the same time to provide for a ready adjustment of the hand piece, to vary the bite or clampingr action of the double chuck and to compensate for wear, without disassembling the hand piece. To this end my improved invention contemplates a different form` of den `in which theiusual pivotal ears are dispensed with altogether, and the pivotal portion of fthe dog is located inthe same plane as the other portions, whereby the dog can be produced by a simple die punching or stamping:operation in one piece without any machining;r whatcven.` My invention contemplates the further` provision `of an adjustable screw disposed axi ally with respect to the chuck closer and en- ,egagingra a notch or reccssin the dog and serving to` prevent lateral play oli' the dog and also to receive the thrust impartediby the dog to the chuck closer which is thereby actuated axially, thus preventingi the possibilityofbindinniinthe sleeve. The adjustable screw in the chuck closer is also located so to be acc ssible from the end` oftheA hand piece through the space normally occupied by the shank of the drill or tool, so thattlie screw can be rotated without disassemblingr the hand piece, thus not only j )roviding for the ready and instantaneous zulj'ustmcnt oi `the hand piece to accommo the shanke of different bits or tools, and to take up wear of the parts, but this also as sists materially in the assemblingof the parts of the hand piece.

date slight variations in the diameters cfm My invention also contemplates the provision on the chuck closer of a transversely disposed recessed portion to receive the angula-r or transversely disposed portion of the dog, for the purpose of preventing the rela-` tive rotation of the dog and chuck closer.

My invention also contemplates other advantageous features,all of which are hereinafter described and clearly'pointed outin the claims.

Referringfto the accompanying drawings, whichillustrate one embodiment of my invention, selected by me for purposes of illustration, v

Figurel represents a sectional view partly in elevation `of a dental hand piece embodying my invention, showingthe same in operative position with respect to a bit or tool.

Fig. 2 is asimilar view showing the parts in open position and the tool removed.

kFig-3 is a detail plan view of the inner stationary Vsleeve of the hand piece carrying the chuck closer'and dog. p

Fig. 4 represents a longitudinal sectional f view of the saidsleeve shown in Fig. 3, the

yposition of my improved dog being Vindicated in dottedlines. Y

Fig. 5 represents a transverse sectlonal View ofthe sleeve shown in Figs. 3 and 4.

a0 1 Fig. 6 is a detail view partly in section,

showing the double chuck, chuck closer, adjusting and abutment screw, the dog operating wedge piece, and parts connected therewith, in separated relation, to facilitate the understanding of my improved invention. Fig. 7 representsy an enlarged sectional view, partly in elevation, showing the relation of the chuck closer, dog, and wedge piece, in they stationary sleeve. ig. 8 is a detail perspective view of the detached. ig. 9 is a detail perspective view of the chuck-closer detached. Y

Referring to the -accompanying drawings, 'i -1 representsthe exterior casing of the hand piece, which yis of ordinary construction and lspreferably roughened on its exterior for a portion of its length, as indicated at 2, in the customary manner. W Ming 1 is the rotary sleeve 3, shown in detail in Figs. 3, 4, and 5, which is provided at its outer end with an aperture 4 to receive Y the qshank'of a bit or drill, of smaller diameter than the interior of the sleeve, the sleeve being provided adjacent to the aperture 4, and inside of the sleeve, With a conical' recess or seat 5, to receive the forward lend of the chuck and compress the jaws thereof upon the shank of the drill or tool when the chuck is subjected to the thrust movement. The rotary sleeve 3 is also provided with an aperture 6 in its wall to receive the fulcrum end of the angular transverse portion of the dog, as indicated in dotted lines in Fig. 4, and the opposite side ithin the casof the sleeve is provided with an elongated slot 7 to accommodate the tail portion of the dog and permit the necessary movement thereof. Adjacent to the aperture 6 the sleeve is also provided with another longifwtudinal slot, indicated at 8, to receive a stop lug on the wedge piece for operating the dog, and this slot 8, 1n conjunctlon with ythe saidk stop lug serves to limit the longitudinal movement of the Wedge piece, while securing their joint rotation.

Within the sleeve 3 is a double chuck, indicated at 9, having its end portions substantially conical, and split longitudinally, in a well known way, so as to provide clamping jaws 10-10 for en aging the shank 11 of a bit or tool 12. ithin the sleeve 3 is also located the chuck closer 13, shown detached inFig. 7, and in perspective, enlarged, in Fig. 9. The chuck closer 13 is provided atits forward end with a conical recessed portion 14, for engaging the rear end of the double chuck, and at its rear end is provided with a transverse slot or recess 15 forming .bifurcated portions between which the transverse portion of the dog lies, thereby' preventing relative rotation between them. The chuck closer 13 is provided with a longitudinal central recess 16 communicating with an axial threaded aperture 17 in which is located a hardened screw 18, preferably of the same diameter throughout, and provided at its forward end with a notch 19 to receive a screw driver therefor, or other means for turning it, and at its rear end with a hardened point 20 for engaging the dog and receive the longitudinal thrust imparted by the dog and transmitted by the chuck closer to the chuck for closing the jaws thereof.

The clutch operating dog comprises a transversely' disposed portion 21 provided on its forward face wlth a notch or recess 22 engaged by the screw 20, and a longitudially disposed tail portion 23 provided with an inwardly extending bearing portion 24 for engaging the longitudinally movable wedge piece. It will be seen that this dog is of extremely simple construction, and

that the tail portion and angular portion are in the same plane so that it can be formed by a simple punching operation in one piece without machining, and without the use of any other tools or hand labor, thus reducing the expense of such dog to an extremely small fraction of the cost of the ordinary dog, which has heretofore been one of the most expensive parts in the hand piece tov manufacture. The outer end of the transverse portion 21 of the dog loosely engages the aperture 6 in the sleeve 3, as clearly shown in Figs. 1, 2, 3, and 4. and forms the fulcrum of the dog, the fulerum bearing for the dog being the engagement of this transverse portion 21 with the rear `or adjusting the hand piece.

For operating the dog, the longitudinally j when in operative position, by the engage-` ment of the screw 18, in the notch 22 of the dog (see Figs. 1 and 2).= This construction provides a very ready means for assembling the parts, as the dog` cantbe placed inv the sleeve 3 while the screw 18i is adjusted to a forward position out of engagement with the dog, and after the partsof the hand piece are entirely assembled and the wedge piece, hereinafter described, is placed in position, the screw 18 can be screwed in to engage the recess 22 in the dog, and holdi the parts in assembled position, as will be readily understood the bifurcated portions of the chuck closer extending on opposite sides of the dog and as the dog is held against rotation with respect to the sleeve by its engagement with the aperture 6,this construction holds the chuck closer against rotation while the screw 181 is turned for the purpose of assembling or disassembling,

movable wedge piece may be employed, the same being indicated at 25, and being formed on a shaft section 26, which is recessed or milled out in the usual manner, as indicated at 27, so as to form the inclined wedging surface 28, of roughened or step form. The shaft section 26 is also rovided with a stop lug 29 which engages t ie slot 8 in the sleeve 3, as hereinbefore stated, the co-action of said lug 29 and slot 8 limiting the longitudinal movement ofthe wedgeV piece 25 and the engagement of the inclined surface 28 with the bearing portion 24 on the tail of the dog, serves to move the tail portion 23 laterally and impart a forward thrust to the screw 18, the chuck closer 14, and the double chuck, to close the jaws of the clutch. The shaft section 26 is preferably connected by a loose joint, indicated at 30, to a shaft 31, which extends through a longitudinally movable inner sleeve 32, or bearing sleeve, thus supporting the shaft and pern'iitting it to rotate. The inner sleeve 32 slides longitudinally with said shaft members upon a key 33 in asupporting sleeve 34, to which the casing 1 is connected, in any usual or preferred way. In the' present instance the casing 1 is shown as slipped over the supporting sleeve 34 and locked in position by a set screw 35, the sleeve and casing being further locked against relative rotary movement by interlocking means, comprising in this instance a screw 36 projecting from the rear end of the casing and fitting in a recess 37 in a boss or hub 38, formed on the rearend of the supporting sleeve. The inner bearing sleeve 32 is provided at its rear end with a threaded portion 39 upon which is screwed the` Casin flexibleishafting lextending rom the rotary member ofthe `dental engine, or other driving means Therearend of the shaft meinbei-31, is provided with abearing portion 40, lying within the threaded portion 39, saidl shaft section 3l being-further provided with a threaded stem 41 which engagesthe rotary shaft ofthe `driving means, in a well known way, for imparting rotarymovement to the shaftsection 3l, the# shaft section 26, the sleeve 3, and thetool clamped or held in said `sleeve by the chuck, chuck closer, and do ,ias will be readily understood.

n the operation of the device it will be understood that the parts are normally in theposition shown in Fig. 2, the jawsof. the clutch being open, the vshaftsections 26 and 31 bein in their most forward positions, witht e stop lug 29 in engagement withf the slot 8 in the rotary sleeve 3, and the dog occupying the position shown in Fig. 2.= In this position it will be seen that a `slender screw driver can be inserted longitudinally through the longitudinal tool receiving aperture and the screw 18 can be adjusted at any time to vary the clamping action of the chuck, to take up wear, or for any other purpose. After a drill shank or other tool is inserted in the chuck; vas indicated in Fig. `1, the operator draws the shaft sections31,26, rearwardly, thereby bringing the wedge piece 25 into contact with the bearing portion 24 of the dog, and forcing the tail of the dog laterally, as shown in Fig. 1, thereby imparting a direct forward thrust on the screw 18 axially of the clutch closer 13, and closing the jaws of the clutch upon the tool. It will also be noted that by meansof the said screw 18, operable as before "described, theparts may be readily assembled by backing out the set screw 18 which gives a convenient opportunity to insert `the dog in the sleeve 3, and the parts assembled in the casing 1, after which the screw 18 can `be screwed to its proper position to engage the notch 22 in the dog and adjust the dog to effect the proper clamping action Vof the chuck.

In order to prevent any lateral motion of ,the shaft member 26, I prefer to provide a washer, indicated at 42, surrounding` the shaft member 26 within the casing 1.

Inorder to prevent therotation of the clutch closer and associated parts, including the inner sleeve 3 and 'shaft sections 31 and 26, while the screw 18 is being adjusted, means are `provided for holding the said parts from rotation. In this instance `I have shown the shaft section 31 provided with an aperture 43 adapted to be brought into registration with apertures 44 in the bearing sleeve 32, so that a bodkin or other pin or projection can be inserted in the said registration apertures 43, 44 when the sleeve and `of the usual shaft are drawnv rearwardly, as shown on Fig. 1, thus enabling the operator to hold the shaft'l from rotary movement, and thus hold the shaft section 261'and sleeve 3 against rotation, while the screw 18y is ad- Y member disposed transversely of the sleeve,v the outer end of said transverse member hav-Y ju'sted. f V

What I claim and desire to secure by Letters Patent is ,1; In a dental hand piece, the combination T'with a casing, a rotary sleeve in the casing,

a clutch havin .a'longitudinal tool aperture, and a longitudinally movable chuck closer in axial aline'ment with the chuck, of a dog for actuating'the chuck closer, comprising an' angular plate having a member disposed'longitudinally of the sleeve and a ing a fulcrum end in the plane of the longitudinal member and engaging *an aperture -in the Wall of the sleeve, the said Vchuck with alcasing, a rotary sleeve in the casing, a chuck having a longitudinal tool'aperture,

v and a longitudinally movable chuck closer,-

in axial alinement with theA chuck, of a dog for actuating the chuck closer, comprising an angular plate having a member disposed longitudinally of the vsleeve ,and

a membervv disposed transversely ofv the sleeve, the outer end of said transverse inem-y ber having a fulcrumv vend. in the planecof the longitudinalmember and engaging an aperture in the wall ofthe sleeve, such chuck closer and vsaid transverse arm being provided, the one with a recess and the other vwith a screw engaging said recess having its axisfcoincidentwith the axis of the chuck vcloser for holding said dog from movement transversely ofthe sleeve, and transmittin@r pressureto the chuck closer axially disposed longitudinally of the sleeve and a member disposed transversely of the sleeve,

the outer end' of said transverse member having a fulcrum 'end in the plane of the longitudinal member, and Vengaging anV aperture in the wall ofthe sleeve, saidy transverse t member being" provided with a recessed portion, said chuck closer being providedv with a longitudinal`axial` aperture communicating with the aperture in the thereof, and actuating means for engagingthe longi- A chuck, and a screw located in a threaded portion of said aperture, and engaging the recess in the transverse member of the dog, to hold the dog from lateral movement in the sleeve and to transmit pressure axially to the chuck closer, and means for actuating the longitudinal member of the dog.

4. In a dental hand piece, the combination with a casing, a rota sleeve in the casing, a Ychuck having a longitudinal tool aperture, and a longitudinally movable chuck closer, in axial alinement with the chuck, of a dog for actuating the chuck closer, comprising an angular plate having a member disposed longitudinally of the sleeve and a member disposed transversely of the sleeve, the outer end of said transverse member having a fulcrum endl in the plane of the longitudinal member, and engaging an aperture in the wall of the sleeve, said transverse member being provided with a recessed portion, said chuck closer being provided with a lon itudinal axial aperture communicating witg the aperture in the chuck, and a 4screwlocated in a threaded portion of said aperture, and engaging the recess in the transversev member of the dog, to hold the dog `from lateral movement in the sleeve and to transmit pressurek vaxially to the chuck closer, means for preventing the rotation of the chuck closer with respect to said sleeve, and means for `actuating the longitudinal member of the dog.

5. In a dental hand piece, the combination with a casing, a rotary sleeve in the casing, a chuck having a longitudinal tool aperture, ,and a longitudinally movable chuck closer, in axial alinement vvith the chuck, of a dog foractuating the chuck closer, com prising an angular plate having a member disposed longitudinally of the sleeve and a member disposed transversely of the sleeve, the 'outer' end of said transverse member having a fulcrum end in the plane of the Vlongitudinal member, and engaging an aperture in the wall of the sleeve, said transverse member being provided with a recessed portion, said chuck closer being provided with la longitudinal axial aperture communicating with the "aperture in the chuck, and a screw located in a threaded portion of said aperture, and engaging the recess in the transverse member of the dog, to hold the dog from lateral movement in the sleeve and to transmit pressure axially to the chuck closer, said chuck closer being provided with bifurcated iportions, extending on opposite sides of the dog and preventing the rotation of the chuck closer in turning said screw, and means for actuating the longitudinal` member of the dog.

" In testimony whereof I aix my signature.

' RUFUs G. s'rANBRoUGH. 

